org.springframework.context.MessageSource Maven / Gradle / Ivy
/*
* Copyright 2002-2019 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.context;
import java.util.Locale;
import org.springframework.lang.Nullable;
/**
* Strategy interface for resolving messages, with support for the parameterization
* and internationalization of such messages.
*
* Spring provides two out-of-the-box implementations for production:
*
* - {@link org.springframework.context.support.ResourceBundleMessageSource}: built
* on top of the standard {@link java.util.ResourceBundle}, sharing its limitations.
*
- {@link org.springframework.context.support.ReloadableResourceBundleMessageSource}:
* highly configurable, in particular with respect to reloading message definitions.
*
*
* @author Rod Johnson
* @author Juergen Hoeller
* @see org.springframework.context.support.ResourceBundleMessageSource
* @see org.springframework.context.support.ReloadableResourceBundleMessageSource
*/
public interface MessageSource {
/**
* Try to resolve the message. Return default message if no message was found.
* @param code the message code to look up, e.g. 'calculator.noRateSet'.
* MessageSource users are encouraged to base message names on qualified class
* or package names, avoiding potential conflicts and ensuring maximum clarity.
* @param args an array of arguments that will be filled in for params within
* the message (params look like "{0}", "{1,date}", "{2,time}" within a message),
* or {@code null} if none
* @param defaultMessage a default message to return if the lookup fails
* @param locale the locale in which to do the lookup
* @return the resolved message if the lookup was successful, otherwise
* the default message passed as a parameter (which may be {@code null})
* @see #getMessage(MessageSourceResolvable, Locale)
* @see java.text.MessageFormat
*/
@Nullable
String getMessage(String code, @Nullable Object[] args, @Nullable String defaultMessage, Locale locale);
/**
* Try to resolve the message. Treat as an error if the message can't be found.
* @param code the message code to look up, e.g. 'calculator.noRateSet'.
* MessageSource users are encouraged to base message names on qualified class
* or package names, avoiding potential conflicts and ensuring maximum clarity.
* @param args an array of arguments that will be filled in for params within
* the message (params look like "{0}", "{1,date}", "{2,time}" within a message),
* or {@code null} if none
* @param locale the locale in which to do the lookup
* @return the resolved message (never {@code null})
* @throws NoSuchMessageException if no corresponding message was found
* @see #getMessage(MessageSourceResolvable, Locale)
* @see java.text.MessageFormat
*/
String getMessage(String code, @Nullable Object[] args, Locale locale) throws NoSuchMessageException;
/**
* Try to resolve the message using all the attributes contained within the
* {@code MessageSourceResolvable} argument that was passed in.
* NOTE: We must throw a {@code NoSuchMessageException} on this method
* since at the time of calling this method we aren't able to determine if the
* {@code defaultMessage} property of the resolvable is {@code null} or not.
* @param resolvable the value object storing attributes required to resolve a message
* (may include a default message)
* @param locale the locale in which to do the lookup
* @return the resolved message (never {@code null} since even a
* {@code MessageSourceResolvable}-provided default message needs to be non-null)
* @throws NoSuchMessageException if no corresponding message was found
* (and no default message was provided by the {@code MessageSourceResolvable})
* @see MessageSourceResolvable#getCodes()
* @see MessageSourceResolvable#getArguments()
* @see MessageSourceResolvable#getDefaultMessage()
* @see java.text.MessageFormat
*/
String getMessage(MessageSourceResolvable resolvable, Locale locale) throws NoSuchMessageException;
}